JP2012503790A - Cable installation device - Google Patents

Abstract

  An apparatus for detecting air flow from an outlet end of a tube sent into the inlet end of the tube, the first bore section having a first size bore size and a second bore size A bore having a second bore section with a first bore section between the first bore section and the second bore section, and a second through the first bore section from the outlet end of the tube An obstruction configured to block air flowing into the bore section of the tube and a securing means for securing the device to the tube so that the bore communicates with the outlet end of the tube. A device in which a pressure sensor is used to compare the air pressure in the first bore section with the air pressure in the second bore section, and the differential pressure indicates the air flow in the bore.

Description

  The present invention relates to the installation of cables such as optical fiber units, wires, electrical cables and the like. In particular, but not exclusively, the invention relates to fiber unit cable blowing through a pre-arranged conduit.

  Optical fibers are widely used in telecommunications systems for high speed information transmission. A fiber unit, which can have a single optical fiber or a bundle of multiple optical fibers, is typically installed in a protective optical conduit having a plurality of optical fiber tubes, which are usually surface boxes. ) Or as a continuous span between convenient access points, such as inspection chambers, already deployed along the desired route.

  As used herein, the expression “cable” includes each optical fiber, fiber unit, and cable having such fiber and fiber unit, as will be appreciated from the description. A “conduit” also includes tubes and tube bores, but primarily refers to a route, or path, constructed or constructed of fiber cable, such routes having multiple tubes. The total length of these tubes is the root.

  The conduits are typically made of plastic, each having a typical inner diameter of 3 to 6 mm, or more, usually given in bundles with up to 24 or more tubes, They are held together in a protective outer sheath. Each fiber conduit tube can receive at least one fiber unit having at least one respective optical fiber. Many conduits and bundles of conduits are pre-installed across the access network and distribution network between the local exchange and the customer premises in a branching network system. Concerning the movement of pushing the fiber link close to the customer's building (eg, fiber for building “FTTP”), the conduit extends further into and into commercial and residential buildings. That is, for example, in the UK where almost all networks have optical fibers that extend as much as possible from the core network to many end customers, this is a fundamental part of the push to FTTP. In order to achieve this, the installation of the optical fiber needs to be speedy, cost effective and work efficient.

  A possible problem during installation is that the fiber unit may not have reached the correct destination position. During installation, the operator is usually accompanied by a large number of conduit tubes, which can cause mistakes in recognizing the correct conduit, especially if the operator is working under adverse manhole and light conditions. This can be even a colored cord conduit that helps direct the operator to the correct conduit.

  For example, in installations using the “feed fiber” method known from EP 108590, the fiber unit is fed into the tube using compressed air. If air is given into the wrong tube, the fiber unit goes out to the wrong place (not at all). Because it is almost impossible to know the exact length of the conduit route in which the fiber unit is installed, the operator cannot know exactly that in a timely manner when an error occurs.

  Currently, the installation of fiber units using the infeed fiber method is relatively labor intensive, requiring at least two operators. One operator is located at the head end of the conduit, where air and fiber units are installed in the conduit mouth during installation, and the other operator is at the remote end of the conduit. In this position, the air and fiber unit exits the conduit mouth. A second remote end operator is necessary because the remote end is often a kilometer or more away from the head end. Therefore, the operator at the head end can determine the remote end condition during installation, in particular whether the air is flowing through the correct tube and whether the fiber unit has reached the target position. It cannot be known without an operator.

  There is known a method by one operator at the head end of the conduit that can detect the arrival of air and subsequently the arrival of the fiber unit at the remote end of the conduit. Some of these have been developed by the applicant and include the methods described in WO2007113549. In this method, an acoustic signal is introduced into a bore in a detection device that is attached to the far end of the tube, thereby communicating the bore with the bore of the tube. The phase shift of the acoustic signal resulting from the air flowing through and along the bore of the detector is detected as an indication of the air flowing from the correct tube. Of course, if no signal change is detected, it strongly indicates that air is being sent from the head end to the wrong tube, or is unlikely, but the device is secured from the far end to the wrong tube. Yes. Although this method works well under optimal conditions, it has been found that changes in field conditions such as temperature affect performance reliability. Another approach is described in WO2007101975, in which a substantially airtight space is provided in the device housing. The rupture of the housing indicates that air is flowing from the far end to the outside of the tube.

  In general aspects, the present invention provides a method and apparatus for installing a cable, such as a fiber optic unit, into a conduit tube, in particular that the air sent to the conduit has reached its intended destination. It also allows a single operator to operate substantially alone to determine that a fiber unit that is continuously fed into the conduit has reached its destination position. The present invention is used where the operator must select one conduit from possible candidates or wants to clearly confirm that the air and fiber unit has reached its intended destination position. be able to.

The first aspect of the present invention provides an apparatus for detecting the flow of air sent into the inlet end of the tube from the outlet end of the tube. This device
A bore having a first bore section with a first size bore size and a second bore section with a second bore size;
Air positioned in the bore between the first bore section and the second bore section and flowing from the outlet end of the tube through the first bore section to the second bore section An obstacle configured to block,
Fixing means for fixing the device to the tube such that the bore communicates with the outlet end of the tube;
In use, an air pressure sensor is used to compare the air pressure in the first bore section with the air pressure in the second bore section, and the differential pressure indicates the air flow in the bore. .

  In some embodiments of the detection device, an air stone is provided so that air flowing out of the far end of the tube exit can exit the device without excessive internal pressure. An obstruction provided in the bore causes the air in the first section to have a different pressure level than the air in the second section. Typically, the air pressure level in the first section is a relatively higher pressure level than in the second bore section. The obstruction may have a physical obstruction within the bore, but in a preferred embodiment it has a narrow portion of the bore that takes the form of a waist or neck, thereby Back pressure is generated in the air flowing from one bore section to the second bore section. The two bore sections can be of different or the same diameter size.

  In a preferred form of air outlet, an air pressure measurement point along the bore is also provided in communication with the two bore sections, and the differential pressure between the two sections is measured using, for example, a pressure sensor or transducer. Can be done. As mentioned above, the back pressure is generated in one preferred embodiment of the device by reducing the size of the bore diameter in the direction of air flow from the outlet end of the tube toward the air stone. . The reduced or narrow bore size can be limited to a particular section of the bore so that other sections of the bore have a constant diameter along their respective lengths.

  In one implementation, the device is further arranged to detect the arrival of a fiber unit or cable as well. This preferably provides a holding section in the device that is configured along the bore to prevent further advancement of the fiber edge (attached to the front end of the fiber unit, as described below). Achieved by: A sensor is provided at or near the holding section that can recognize the presence of the fiber edge. The edges are made of metal, as is usually the case, and the sensor can have an induction coil looped around or around the retaining section in the bore. As a further preferred feature, a signal transmission unit in the form of a radio unit or other telecommunication component can be included to signal the arrival of at least one of air and fiber to the head end, and A microprocessor may be included that assists in determining and detecting at least one of air and fiber reaching the far end.

A second aspect of the present invention provides a method for detecting air flow from the outlet end of a tube. This method
Fixing the device to the tube such that a bore in the device of the present invention communicates with the outlet end of the tube;
Sending air into the inlet end of the tube;
Blocking air flowing from the outlet end of the tube through the first bore section of the device to the second bore section of the device;
Comparing the level of air pressure in the first bore section and in the second bore section;
Signaling the differential pressure from the comparison to indicate an air flow in the bore.

  Preferred embodiments of the invention are described below by way of example with reference to the accompanying drawings.

FIG. 1 is a schematic diagram of the components used in the installation of a feed fiber according to the prior art. FIG. 2 is a cross-sectional view of the detection apparatus according to the present invention. FIG. 3 is a view showing the detection device without a housing. FIG. 4 is three views from different angles of the detection device including the housing. FIG. 5 is a flowchart showing functional steps using the detection apparatus.

  A simple schematic of the components used to install an optical fiber using infeed fiber technology is shown in FIG. In this installed head end there is a feeding head (2) with mechanical drive means, which pushes the optical fiber unit, ie the cable, towards the tube, ie the conduit (6), towards the far end. The infeed head assists this task with compressed air that is sent into the conduit using an air compressor (4) so that at least a portion of the fiber units in the conduit are fed through the conduit. An “airstone” (8) is secured to the far end of the conduit. This has a barrier of porous compressed particulate material and allows air to pass through, but stops the continuous progression of the fiber unit beyond the barrier.

  As stated above, a typical process involves a first engineer operating a feed head, a compressor positioned at the head end, and a second engineer positioned at the far end. The second engineer said that (i) the correct conduit was selected at the headend so that the air from the compressor would flow out of the desired tube mouth, thereby allowing the process to move to the fiber installation stage. (Ii) Send a signal (10) to the first operator to confirm that the fiber unit has exited the fiber mouth and the installation process can be terminated. This signal transmission can be performed using any method such as a mobile phone, a walkie-talkie, or the like.

  In the method and apparatus of the present invention described below, the air and fiber detection process and signal transmission (10) are automated.

  FIG. 2 is a view showing a cross section of an embodiment of the detection device (20) according to the present invention. An air stone (8) made of air-porous material is provided in the housing (22) of the device. In use, the far end of the tube (6) is engaged with the receiving part (5) of the device using a conventional replaceable collet tube connector so that the bore of the tube is in the air as shown. Communicate with the bore (24) of the device leading to the stone. When the correct tube or conduit is selected at the headend, air inevitably flows through the device bore and into the device as illustrated by the dotted arrows. (Of course, if the wrong tube is selected at the head end, air will not flow to the device.) This air passing through the air stone in a known manner is shown in FIG.

  The detection device further comprises a pressure sensor or transducer (26) configured to detect changes in air pressure and pressure levels in the bore (24). The bore (24) of this device is contoured along its length, as shown in FIG. 2, with a reduced or narrowed portion having a reduced cross-sectional area relative to the adjacent section immediately adjacent to the bore. (32) Two air outlets (28, 30) are provided in communication with the bore. The first outlet (28) allows air to exit at a predetermined point before the air reaches the narrow section of the bore, and the second outlet (30) is a predetermined point after the narrow section. Is provided.

  Another view of the device (20) is shown in FIG. This figure shows a narrow section (32) of the bore connecting from the receiving part (5) with which the conduit is engaged to the air stone (8) at the opposite end, without a housing of the apparatus. Show. The two air outlets (28, 30) are connected to the pressure transducer (26) by a tube (50). The air flow entering or leaving the device is again illustrated by dotted arrows.

  During the installation process, the engineer proceeds to the far end and attaches the device to the conduit mouth, which causes the conduit bore to communicate with the device bore to start the device. The engineer then proceeds to the headend to begin the installation process. If the correct conduit is selected at the head end, air will inevitably flow from the conduit mouth at the far end into the bore (24) of the device. When air flows through the narrow section (32) of the bore, back pressure is generated, which increases the air pressure level in the bore just before the narrow section near the first air outlet (28). . In contrast, the air pressure level in the bore near the second air outlet (30) is lower due to its position beyond the narrow portion (32). The pressure transducer is arranged to compare the pressure level P1 of air exiting through the first air outlet (28) with the pressure P2 of air exiting through the second air outlet (30). . The detected air differential pressure allows calculation of the air flow rate in the bore.

  If this detected air flow rate deviates from the reference, ie, baseline air flow rate (or range), this means that air is flowing from the conduit mouth and to the far-end device. It serves as a clear and clear instruction. The reference value is given as a comparison for such purposes, but is preferably calibrated under still air conditions (or with air flowing at a flow rate less than the detected flow rate). Where there is sufficient air movement through the bore, the air pressure differences P1 and P2 are substantial or relatively small.

  The reference value is determined during the installation session itself, prior to the arrival of air at the far end, based on the start of the device, when the air in the device is relatively static air in the bore at this stage. Can be generated. More preferably, the calibration process is performed in relatively severe still air conditions, for example, in a manufacturing environment as part of the manufacturing process. The value of the reference value is based on the arrangement of the specific detection device, the contour shape of the bore, and in particular the narrow portion thereof, and the arrangement between the devices can include a change in dimensions.

  The output of the pressure transducer is sent to and monitored by the microprocessor (48). Its functions and processes proceed as described in detail below with respect to the flowchart of FIG.

  Based on the confirmation that the detected air flow is excessive or otherwise deviates from the reference flow value by a predetermined amount, the microprocessor instructs the signal transmission module (34). And check with the engineer at the headend that air is flowing from the correct conduit to the remote end. In a preferred embodiment, the signaling module transmits a mobile phone message that can take the form of a short message service (SMS) text message, or more preferably a pre-recorded voice message. This is less noticeable by the headend operator and is more preferential than SMS text. The person skilled in the art will understand other signal transmission methods, for example using radio signals, which can be deployed for this purpose. Upon receipt of the confirmation signal, the engineer can proceed to the next stage of installation to install the fiber unit.

  It is known to attach a “bead” to the front end of the fiber unit to be installed. Such an edge is typically made of a metal such as brass or aluminum, which can be reached when the fiber is fed through a conduit and when the tip reaches and is within the air stone (8). When housed, the otherwise exposed fiber tip is protected from damage.

  A method for detecting the arrival of a fiber is described in WO2007113544. This disclosure is incorporated herein by reference and is employed in the design of the device. Referring back to FIG. 2, the device has a metal coil (40) wrapped around the device bore at or near the narrow section (32). This coil forms part of an LC oscillator that resonates at a predetermined constant frequency. This coil provides a variation in the tolerances of the detection device and ensures that the manufacturing process is fully sensitive to ensure sufficient sensitivity for reliable edge detection of various metal edge materials. Ideally calibrated as part.

  The coil is located in a narrow portion of the device bore, which is sized to prevent further advancement of the edge along the device bore. Based on the fiber and edge reaching the device, the edge is hooked and held in a narrow section of the bore. Its proximity to the coil acts as a metal core that changes the inductance of the coil and the Q value of the oscillator. Since changes in inductance and Q-factor change both frequency and amplitude, one or both of these can be monitored using a comparator to give the operator a clear indication of the arrival of the fiber at the far end. (Changes in amplitude are typically relatively large, but it can be easy to monitor and are preferred), and this is described above with respect to detecting the arrival of air. Can be signaled in the same way as

  In this embodiment, the induction loop is made of a very fine copper wire coil having a diameter of about 0.2 mm, and this coil is on the order of 15 turns. However, neither the precise rotational speed nor the size of the copper wire is important to the present invention, and the rotational speed used is related to the coil diameter.

  Modifications are possible within the scope of the invention. In the above description, the coil is preferably located in or near the narrow portion of the bore, which has the purpose of producing a differential pressure that can be detected as an indication of air flow; For the purpose of functioning as a retainer for the edge of the fiber unit, it serves two purposes of reducing the size of the bore of the device. However, the coil can be located anywhere in the device as long as the edge of the fiber is close enough to be able to be held, for example, in an air stone, or the edge can Allows recording of moments indicating passing or other changes in coil inductance.

  Different materials cause the oscillator to resonate at different frequencies. In the present embodiment, the coil responds to the arrival of edges made of various metals such as aluminum, brass, steel or copper. Other edge material types can provide alternative fiber unit arrival detection methods. For example, by using a magnetic sensor instead of an induction coil, a magnetic material (which does not need to contain a metal) or a material containing iron (any metal exhibiting ferrimagnetic or paramagnetic properties may be suitable) It can be detected like a Hall probe that causes a change in the magnetic flux of the magnetic sensor.

  FIG. 4 is a diagram showing an embodiment of a detection device (20) having a housing (22) thereon. These figures also show the start button (42) and stop button (44) of the device and the display screen (46).

  The size of this device is roughly the size of a match box (approximately 85 x 60 mm cross-sectional area x 180 mm long), inside it a pressure transducer (26), a signal transmission unit (34), a microprocessor and associated electronic components, And an induction coil. A power source (eg, a battery) is also included, and there is an antenna for transmitting a confirmation signal to the conduit headend. Those skilled in the art will appreciate that some or all of these components can have separate parts or devices located outside the housing, but are connected here in use. I will. Furthermore, the features of the device and the present invention make it possible to position the components in various ways and at various positions relative to each other in order to further obtain the advantages of the present invention.

  The flowchart of FIG. 5 illustrates a process for detecting and signaling both the arrival of the collected conduit far end air and the arrival of the fiber unit. In this embodiment, the microprocessor effectively performs one or both processes, but those skilled in the art will recognize that the user has the necessary steps and additional steps to avoid performing all or part of the automation process experienced by the processor. It will be understood that at least one of these steps can be selected manually.

  As stated above, the process begins with the operator proceeding to the far end, installing the device at the end of the conduit, and being initiated by pressing the “Start” or “On” button (42) ( Step S1), then the device initializes itself (Step S2). When it is detected that this is the first start (step S3), a reference value (minimum amount) of air flow value is set for use in determination (steps S4, S5), and the air enters the far end. When reached, the differential pressure is measured as described above (step S6). As illustrated in the flow chart, one preferred implementation is to have a clear and clear sign of air arrival before the air flow in the bore or cavity of the device communicates an air arrival signal from the far end (step S9). (Steps S7, S8) includes a step of detecting that the level is stable above the minimum amount level of the reference value.

  In a preferred embodiment, the detection device is arranged to meet the “test” requirement as shown in the flowchart (steps S10 to S13). It can be recalled that the head end and the remote end are at a considerable distance from each other. This device mode allows the engineer to check that the device is powered on at the far end. The engineer may have forgotten to turn on the device in the first place, or it may have been a long time without signal coming from the far end, You may be sending air to the sensor or the detector may not be on or working properly. By pressing the “test” button for a long time (steps S10, S11), the far-end device sends a reply to the request for the test message using the signal transmission method described above (if possible) (Step S13).

  Upon receipt of the “end to air” confirmation signal (sent in step S9), the session proceeds to the fiber installation stage, where the presence of the edge of the edged fiber is detected by detecting a change in frequency or coil inductance. The When the fiber edge is detected (step S20), a confirmation signal is sent to the head end (step S21) and the installation is terminated by the engineer at the head end by turning off the feed head and compressor. Can do. The engineer then moves to the remote end to remove the detection device from the far end. It is possible to automate part of the termination process so that based on receiving a signal that air has reached the remote end, the infeed head can begin moving the fiber into the conduit or the device They can be at least one of being able to stop themselves upon receipt of a signal that the unit has arrived.

  In the preferred implementation, a selective receiver registration process is provided. This allows the engineer's receiving device (eg, GSM® mobile phone) to be registered with the detection device, as shown in the flowchart (steps S23, S24), to the engineer at the headend. Reach the signal from the far end. A mobile phone number or the like is stored in the GSM module and is read at the start of the device and whenever a serial message is sent from the GSM module to the processor of the main detection device, it indicates that the number has been updated. This message is transmitted by the microcontroller's serial communication buffer to check for possible number updates approximately once per second.

  The devices and methods described to be deployed at the remote end are also performed in other ways (ie, excluding some of the above steps or including steps not mentioned). be able to. Further, the installation device may have components or components not explicitly shown above. In particular, with regard to suitable deformations, the detection device can be formed as a sleeve that is used as a connector at an intermediate point along the conduit route for detection of the path experienced by the air flow. This allows the operator to track the progress and movement of the air and fiber units for further or other purposes related to installation of the feed fiber, such as in the detection of gaps leading to air leaks in the conduit tube network. Make it possible.

  While the particular description of the installation of the feed fiber has been developed specifically for air flow arrival and velocity detection, those skilled in the art will be aware of the presence and speed of fluid flow, or for gas, water or oil. It will be appreciated that the apparatus and method may be applied in other contexts and industries related to installation detection, such as in conduits and pipes.

  In this application mode in the description of the installation of the feeding fiber, the use of a detection method without moving parts is particularly effective. This is because the movable detection device can prevent the air flow and movement in the tube. The sensor itself can be affected by air and by debris, in particular by the microspheres covering the fiber unit (these increase the effect of viscous resistance during installation and also degrade the fiber unit. Can be fed along the conduit by compressed air).

  The methods, apparatus, and structures described above and illustrated in the drawings are merely for ease of explanation and are not meant to limit the invention to any particular embodiment. It will be apparent to those skilled in the art that various procedures and modifications in the methods and apparatus described above are possible within the scope of the invention as disclosed. Similarly, the present invention can be used in various similar scenarios and for various types of cables. In particular, the apparatus and method for air arrival detection and fiber unit arrival detection work together effectively in a preferred embodiment. However, the air reaching method and technique can be used in particular independently of the fiber reaching method.

Claims (15)

A device for detecting the flow of air sent into the inlet end of the tube from the outlet end of the tube,
A bore having a first bore section with a first size bore size and a second bore section with a second bore size;
Air positioned in the bore between the first bore section and the second bore section and flowing from the outlet end of the tube through the first bore section to the second bore section An obstacle configured to block,
Fixing means for fixing the device to the tube such that the bore communicates with the outlet end of the tube;
In use, an air pressure sensor is used to compare the air pressure in the first bore section with the air pressure in the second bore section, and the differential pressure indicates the air flow in the bore. apparatus. A first air outlet in communication with the first bore section;
A second air outlet in communication with the second bore section;
In use, the air pressure sensor detects the pressure of air flowing from the first bore section through the first air outlet and the air flowing from the second bore section through the second air outlet. The apparatus of claim 1 for comparing pressure.   Apparatus according to claim 1 or 2, further comprising a breathable barrier located at one end of the bore of the apparatus away from the securing means.   4. A device according to any one of the preceding claims, wherein the obstacle comprises a narrow portion of the bore.   The apparatus of any one of claims 1 to 4, wherein the first size bore size is different from the second size bore size. A holding section for holding the edge of the fiber exiting the outlet end of the tube and entering the bore of the device;
6. A device according to any one of the preceding claims, comprising a sensor located at or proximate to the holding section for detection of an edge of the fiber in the bore.   The apparatus of claim 6, wherein the retaining section is located in the narrow portion of the bore.   8. Apparatus according to claim 6 or 7, wherein the fiber edge sensor comprises an induction coil that is part of an LC oscillator operatively connected to the apparatus.   2. A signal transmission unit configured to remotely signal, in use, at least one of the presence of air flow in the bore and the retention of the fiber edge in the retention section. Or any one of 8 devices.   The apparatus of claim 9, wherein the signal transmission unit is a GSM portable communication device.   11. The apparatus of any of claims 1-10, wherein at least one of the pressure sensor and the fiber edge sensor is operatively connected to a processor configured to detect air flow in the bore. .   12. Apparatus according to any one of claims 9 to 11, wherein the processor is further configured to drive the signal transmission unit. A method of detecting the flow of air from the outlet end of a tube,
Fixing the device to the tube such that a bore in the device of any one of claims 1 to 12 communicates with the outlet end of the tube;
Sending air into the inlet end of the tube;
Blocking air flowing from the outlet end of the tube through the first bore section of the device to the second bore section of the device;
Comparing the level of air pressure in the first bore section and in the second bore section;
Signaling the differential pressure from the comparison to indicate air flow in the bore.   Initializing the device by comparing the air pressure in the first bore section with the air pressure in the second bore section before sending air into the inlet end of the tube. 14. The method of claim 13, comprising. Sending a fiber unit with a covered fiber edge into the inlet end of the tube;
Using a fiber edge sensor to detect retention of the fiber edge within a holding section in the device;
15. The method of claim 13 or 14, further comprising signaling the presence of an edge of the fiber in the device to indicate that a fiber unit has reached the outlet end of the tube.

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